Buyout firm Hellman & Friedman LLC is nearing a deal to buy collision-repair chain ABRA Auto Body & Glass from its current private-equity owner, according to people familiar with the matter.

Hellman & Friedman won an auction to buy ABRA from Palladium Equity Partners LLC, which first invested in the company in 2011, the people said. ABRA is expected to fetch more than $500 million in the sale, some of the people said.